Metal azo dyestuffs and a process for their manufacture



Patented May 30, 1939 PATENT OFFICE METAL AZO DYES TUFFS AND-A PROCESSFOR THEIR MANUFACTURE Walter Wehrli, Basel, Switzerland, assignor to thefirm of Basel, Switzerland Chemical Works formerly Sandoz,

No Drawing. Original application July 22, 1935,

Serial No. 32,671.

Divided and this application April 2, 1936, Serial No. 72,447. InGermany July 28, 1934 8 Claims.

This application is divisional of my application Ser. No. 32,671, filedJuly 22, 1935, Patent No.

The present invention relates to new azo dyestuffs and to a process fortheir manufacture.

It has been found that new azo dyestufis capable of forming complexmetal compounds on after-treatment with metal yielding agents can beprepared by coupling a diazo compound prepared from an amine of thearomatic series and containing in the ortho position to the diazotizableamino group at least one group of the general formula:

I /acyl wherein acyl I represents sulphoalkyl, sulphoaryl andsulphoaralkyl and acyl II represents an organic acyl radical, with acoupling component or an azo dyestuff capable of coupling, and bysubjecting the azo dyestufi thus obtained to a treatment withsaponifying agents in order to-split off the acyl group II. In thismanner azo dyestuffs will be obtained which possess the general formula:v

NIN

5 wherein R1 represents alkyl, aryl and aralkyl, R2 represents a radicalof an aromatic amine, R3 represents a radical of an aromatic,heterocyclic or aliphatic compound and X represents a group contiguousto the azo group and selected fom the class consisting of hydroxy,alkoxy, carboxy, amino, alkylarnino, aralkylamino and arylamino groups.

The azo dyestuffs prepared by the present process can like therespective o-hydroXy-azo dyestuiis be afterchromed on the fibre, wherebythe shade becomes deeper and the properties become improved. By treatingthe new dyestuffs in substance with compounds yielding chromium, copperor other suitable metals, they bind the metal in complex form and givewater-soluble or insoluble metal-containing dyestufis that can be usedfor various purposes, for example for dyeing textiles or leather or forthe manufacture of lakes and varnishes.

The diazo compounds which can be used in the present process areprepared in the usual manner from amines of the general formula:

acyl I wherein R represents an aromatic nucleus, which may containsubstituents such as halogen, alkyl, sulpho, nitro, hydroxy, carboxy,alkoxy, alkylamino, acylamino, arylamino, aralkylamino groups.

The diacylated amino group may contain identical or difierent acylgroups, whereby acyl I must be a radical of an alkylsulphonic acid, suchas methane sulphonic acid, ethane sulphonic acid etc., or of an arylsulphonic acid such as benzene sulphonic acid, toluene sulphonic acid,naphthalene sulphonic acid, etc., which may be substituted in the arylnucleus and contain groups such as halogen, nitro, acylamino,alkylamino, hydroxy, alkoxy, carboxy etc., or of an aralkylsulphonicacid such as benzylsulphonic acid or its derivatives. The acyl group IImay be one of the above cited radicals or be derived from an organiccarboxylic acid such as acetic acid, formic acid,,b enzoic acid,naphthoic acid, oxalic acid etc.

The diazotation of theo-aminodiacylamino-derivatives is carried out inthe usual manner, and the diazo compounds obtained are coupled in analkaline, neutral or acid medium with such compounds of the aliphatiaromatic or heterocyclic series that contain at least one hydroxy,alkoxy, carboxy, amino, alkylamino, aralkylamino or arylamino group andare able to couple with the diazo compounds in an ortho-position to oneof the groups listed above.

Such compounds are for example the derivatives of the ac-eto aceticacid, hydroxy-, alkoxy-, aminoand amino-hydroxy compounds of thebenzene, naphthalene, anthracene' and carbazol series, their sulphonicand carboxylic acids and their halogenated, nitrated, alkylated andhydroxalkylated derivatives.-

It is further possible to use coupling components such as azo dyestufiscontaining a hydroxy, alkoxy, carboxy, amino, alkylated, aralkylated oracylated amino group and which couple with diazo compounds inortho-position to the above listed groups.

Instead of coupling the diazo compound prepared from ano-amino-diacylamino compound without influence on the acyl rest I. Ifthe formation of the dyestuff has been carried out in a. carbonatealkaline medium, it is generally sufficient to heat it for a certaintime with the mother liquor in order to obtain a complete splitting ofthe acyl group II. By heating the diacylamino dyestufis before or aftertheir isolation with a diluted caustic soda lye, the saponification andelimination of the acyl rest II occurs very rapidly.

Sometimes it is advantageous to combine the saponification with theintroduction of metals, this especially in cases where the introductionof metals into the dyestuffs is carried out in an alkaline bath.

In order to introduce one or several metals into the monoor polyazodyestuffs prepared according to the present process, the dyestuffs areheated with suitable compounds adapted to yield metallike chromium,copper, zinc, tungsten, uranium, aluminium, tin, titanium, molybdenum,vanadium, cerium, manganese, iron, cobalt and nickel.

The production of the complex metal compounds can be carried out on thefibres or in substance. In .order to produce for instance a chromiumcomplex in substance, a monoor polyazo dyestuff prepared as describedabove is heated in an open vessel or under pressure with a chromiumyielding substance such as chromium fluoride, chromium acetate, chromiumsulphate, chromium formate, chromium hydroxides, alkali metal chromites,in an aqueous solution or suspension or in presence of organic solventssuch as glycerine, ethanol, pyridine and in a neutral or acid oralkaline medium.

If the introduction of the metal into the azo dyestufi is carried out inan acid medium, acids such as oxalic acid, acetic acid, formic acid,sulphuric acid will be used. By working in an alkaline medium, alkalinereacting substances such as alkali metal carbonates and hydroxides,ammonia and pyridine can be employed.

The quantity of the metal used for the preparation of complex metalcompounds may vary in wide limits and be for instance of 1 mol. of metalto 1 group capable of giving a complex metal compound or less than 1 to1, for instance of 1 mol. of metal to 2 complex forming groups, or morethan 1 mol. of metal to 1 complex forming group.

The above statements given for chromium are also applicable in the caseof manufacture of copper complex compounds, whereby different coppersalts or hydroxides can be used and whereby the formation of the complexcompounds can be carried out in a neutral, alkaline or acid medium.

The dyestuffs prepared according to the present invention are isolatedfrom the reaction medium in which they have been prepared by the usualmethods, say by salting them out or by precipitating them from theirsolutions by means of acids.

As the present invention allows to prepare a great number of differentdyestuffs, their coloration in dry state may vary from yellow to darkshades. They can be used for various purposes and dye textile fibres ofcellulosic or animal origin yellow to black shades.

One object of the present invention is, therefore, a process for themanufacture of azo dyestuffs comprising the steps of diazotizing anoaminodiacyl-amino compound of the aromatic series of the above citedconstitution, coupling it with such a coupling component of thealiphatic, aromatic or heterocyclic series containing at least onehydroxy, alkoxy, carboxy, amino, alkylamino, aralkylamino. or arylaminogroup and being able to couple with the diazo compound in anortho-position to the above said groups, and subjecting thediacylamino-azo dyestuff thus obtained to a treatment with saponifyingagents in order to eliminate one of the acyl groups.

Another object of the present invention is a process for the manufactureof complex metal compounds consisting in treating the azo dyestuffsobtained as herein above described with metal yielding compounds in thepresence of water and/or organic solvents and in closed or open vesselsat temperatures from 20 to 200 C. and in a neutral, acid or alkalinemedium.

Still another object of the present invention is a process consisting intreating diacylaminoazo dyestuffs prepared as herein above describedwith metal yielding compounds in presence of an alkali, whereby thesaponification of an acyl group and the introduction of the metal intothe molecule of the azo dyestuff occurs simultaneously.

Still another object of the present invention is a process for themanufacture of metalliferous azo dyestuffs, consisting in treating themonoacylamino azo dyestuffs, prepared as hereinabove described, withsubstances yielding chromium and copper under the conditions set forth.

Still another object of the present invention are the azo dyestuffs ofthe general formula:

NZN

wherein R1 represents alkyl, aryl and aralkyl, R2 represents a radicalof an aromatic or heterocyclic compound, R3 represents a radical of anaromatic aliphatic or heterocyclic compound, and X represents a groupcontiguous to the azo group and selected from the class consisting ofhydroxy, alkoxy, carboxy, amino, alkylamino, aralkylamino and arylaminogroups.

Still another object of the present invention are the azo dyestuffs ofthe general formula:

NZN wherein R1 represents alkyl, aryl and aralkyl, R2 represents aradical of an aromatic compound, R3 represents a radical of an aromatic,aliphatic or heterocyclic compound, and X represents a group contiguousto the azo group and selected from the class consisting of hydroxy,alkoxy, carboxy, amino, alkylamino, aralkylamino and arylamino groups.

Still another object of the present invention are the metalliferous azodyestuffs derived from azo dyestuffs of the general formula:

wherein R1 represents alkyl, aryl and aralkyLRz represents a radical ofan aromatic compound, R3 represents a radical of an aromatic, aliphaticor heterocyclic compound, and X represents a group contiguous to the azogroup and selected from the class consisting of hydroxy, alkoxy,carboxy, amino, alkylamino, aralkylamino and arylamino groups and whichcontain in their molecule a metal capable to form complex compounds andselected from the group consisting of chromium, copper, vanadium, nickeland cobalt.

Still another object of the present invention are the azo dyestuffscontaining chromium in complex linkage and derived from a dyestufi" ofthe general formula:

NEN

wherein R1 represents alkyl, aryl and aralkyl, R2 represents a radicalof an aromatic compound, R3 represents a radical of an aromatic,aliphatic or heterocyclic compound, and X represents a group contiguousto the azo group and selected from the class consisting of hydroxy,alkoxy, carboxy, amino, alkylamino, aralkylamino and arylamino groups.

Still another object of the present invention 7 are the azo dyestufiscontaining copper in complex linkage and derived from a dyestuif of thegeneral formula:

wherein R1 represents alkyl, aryl and aralkyl, R2 represents a radicalof an aromatic compound, R3 represents a radical of an aromatic,aliphatic or heterocyclic compound, and X represents a group contiguousto the azo group and selected from the class consisting of hydroxy,alkoxy, carboxy, amino, alkylamino, aralkylamino and aryl amino groups.

Still another object of the present invention is a process for dyeingtextile fibres and leather fast tints, consisting in dyeing the textilefibres -with monoacylamino-azo dyestufis and aftertreating the dyeingsthus obtained with compounds yielding chromium or copper, preferably inpresence of acids.

Still another object of the present invention is a process for dyeingtextile fibres and leather fast tints, consisting in dyeing these goodswith complex metal compounds of the azo dyestuffs prepared as hereinabove particularly described.

The following examples illustrate the present process, the parts beingby weight:

EXAMPLE 1 43 parts of 2-di-p-toluenesulphamino-5-methyl-l-aminobenzeneare diazotized in the usual manner with 6.9 parts of sodium nitrite and25 parts of hydrochloric acid and coupled in presence of sodiumcarbonate with 25.6 parts of 4'-. sulphophenylmethylpyrazolone. Afterthe coupling has occurred, the precipitated dyestuff, which isdiflicultly' soluble in water is filtered, pasted with some water andheated up to C. with a 5% aqueous solution of caustic soda. During thistreatment the dyestufi goes in solution and the elimination of ap-toluene-sulpho radical has soon occurred. The reaction mixture is thencooled down, neutralized with hydrochloric acid and the precipitateddyestuff filtered and dried.

In the dry form it is a yellow powder, dyeing wool from an acid bathyellow shades, which become transformed by afterchroming into abrownish-red.

By using in this example instead of 4'-sulphophenylmethylpyrazoloneother sulphonated or carboxylated pyrazolone derivatives, similarproducts will be obtained, for instance when 2,5-dichloro-4'sulphophenylmethylpyrazolone is employed, a dyestufi will be obtained,which dyes wool from an acid bath greenish-yellow shades.

By using as coupling component the Neville- Winther acid instead of thepyrazolone a dyestufi will be obtained, which is a red powder, dyeingWool orange-red shades, which become violet on after-chroming.

Similar tints will be obtained with dyestuffs prepared from othernaphtholmonosulphonic acids such as 1,5-naphtholsulphonic acid, 1,3-naphtholsulphonic acid, 2,6-naphtholsulphonic acid and2,5-naphtholsulphonic acid.

EXAMPLE 2 EXAMPLE 3 10 parts of the dyestuif prepared as described inExample 2 are dissolved in 50 parts of water and heated with 3.6 partsof chromium formate and 2 parts of formic acid until the formation ofthe chromium complex has occurred. The metalliferous dyestuif thusobtained is then isolated in a usual manner and dried. In the dry stateit is a dark-violet, water-soluble powder, dyeing Wool from an acid bathred-violet shades.

EXAMPLE 4 31.8 parts of 2-acetyl-p-toluenesulphamino-5-methyl-l-aminobenzene of the formula:

are diazotized in the usual manner and coupled in presence of sodiumcarbonate with 1,4-naphtholmonosulphonic acid. After the coupling hasoccurred, 25 parts of caustic soda lye are added to the solution and thewhole is heated during one hour at about 90 C., whereby thesaponification of the acetyl group takes place. The solution is thenneutralized with acid and the dyestufi isolated and dried. It is a redpowder, dyeing wool from an acid bath orange-red shades. Byafter-chroming violet tints will be obtained. The dyestuff preparedaccording to the present example is identical with the dyestuff obtainedaccording to Example 1 from2-di-p-toluenesulphamino-5-methyl-l-aminobenzene and1,4-naphtholmonosulphonic acid.

EXAMPLE 5 45 parts of 2 di p toluenesulphamino-S- chloro-l-aminobenzeneare diazotized in the usual manner and coupled with 22.4 parts ofZ-naphthol-6-sulphonic acid. The saponification of the dyestufi thusprepared is carried out in the manner described in Example 1 and thedyestufi isolated and dried. It is a dark powder dyeing woolorange-brown shades which are transformed into violet by-after-chromingand into red shades on treatment with copper salts.

EXAMPLE 6 I 45 parts of 2 di p toluenesulphamino 5 chloro-l-aminobenzeneare diazotized and coupled with 30.4 parts of 2-naphthol-6,8-disulphonicacid in presence of sodium carbonate. After saponification in the mannerabove described and isolation, a red powder, dyeing wool orange shades,which become red-violet by afterchroming, will be obtained.

EXAMPLE 7 V 65 parts of the dyestufi prepared according to Example 6 aredissolved in 300 parts of water and heated in an autoclave to 100-150 C.with a solution of 12 parts of chromiumoxide in 24 parts of sulphuricacid of 66 B. and 100 parts of water. After the formation of thechromium complex compound has occurred, the dyestuff is isolated anddried. It is a dark powder dyeing wool from an acid bath red-violetshades.

EXAMPLE 8 17.3 parts of sulphonic acid are diazotized and coupled in theusual manner with 11 parts of resorcinol in presence of sodiumcarbonate. The monoazo-dyestufi thus obtained is then combined with adiazo compound prepared from 45 parts of2-di-p-toluenesulphamino-5-chloro-l-aminobenzene and the disazo dyestuifthus produced is saponified as above described and isolated. It is abrown powder, dyeing wool from an acid bath orange-brown shades, whichare transformed into brown by after-chroming.

This diazo dyestufi can easily be transformed into its chromium complexcompound by treating it with chromium yielding substances. Themetalliferous dyestuff thus obtained dyes wool brown shades.

EXAMPLE 9 49.6 parts of2-di-p-toluenesulphamino-l-amino-benzene-5-sulphonic acid are diazotizedin the usual manner and coupled with 14.4 parts of c-naphthol inpresence of sodium carbonate. The saponification of the dyestuff thusobtained is then carried out as above described and the dyestufiisolated. It is a red powder, dyeing wool brown-red shades. Byafter-chroming the same become transformed into violet shades.

EXAMPLE 10 49.6 parts of 2-di-p-toluenesu1phamino-1-amino-benzene-5-sulphonic acid are diazotized in the usual manner andcoupled in presence of sodium carbonate with 10.8 parts ofm-phenylenediamine. The saponification and isolation of the dyestuff isthen carried out as above described, whereby a red-brown powder, dyeingwool orange shades, is obtained. By afterchroming brown shades areobtained.

By coupling of the above diazo compound with phenylmethylpyraz'olone andsaponification of the mono-azo-dyestufi, a yellow powder dyeing woolyellow shades, which become orange on after-chroming, will be obtained.

EXAMPLE 11 37.5 parts of the compound of the formula SOzCHa 01 arediazotized and coupled in presence of soda with 22.4 parts of1,4-naphtholsulphonic acid. By heating the monoazo dyestufi thusobtained in soda-alkaline mother-liquor, the saponification occurs andthe dyestuff can be precipitated by acidulation of the solution. In thismanner, a red powder dyeing wool orange-red shades, that become violetby after-chroming, will be obtained.

EXAMPLE 12 29.2 parts of the compound of the formula:

CH3 are diazotized in the usual manner and coupled in presence of sodiumcarbonate with 25.6 parts of 4'-sulphophenylmethylpyrazolone. Thesaponification and isolation of the dyestuff can be carried out in amanner described above, whereby a yellow powder, dyeing wool yellowshades, that become orange on after-chroming, will be obtained.

EXAMPLE 13 18.4 parts of benzidine are tetrazotized in the usual way andcoupled in presence of sodium carbonate with 13.8 parts of salicylicacid. The intermediate product thus obtained is then combined inpresence of alkali with the saponified monoazo dyestufi prepared from49.6 parts of 2 di-p-toluenesulphamino-l aminobenzene-5- sulphonic acidand 11 parts of resorcinol, and the trisazo dyestuff thereby produced isisolated in a usual manner.

The same dyestufi can be prepared by coupling the intermediate productobtained from benzidine and salicylic acid, with the non-saponifiedmonoazo compound prepared from Z-di-p-toluenesulphamino-l aminobenzene-5sulphonic acid and resorcin, and subjecting the trisazodyestufi to asaponification process.

In dry state the dyestufi is a dark powder,

dyeing cotton and-regenerated cellulose brown shades, which becomedarker when aftertreated with copper salts. The complex copper. compoundof this dyestufi can easily be produced in substance by treating thedyestufi with copper yielding compounds. 'Ihecompler; copper compound isa water soluble dark powder, dyeing cotton, regenerated cellulose andnatural silk brown shades.

EXAMPLE 14 43 parts of 2-di-p-toluenesulphamino-5-meth- The monoazodyestuff thus obtained can further be diazotized and coupled with anycoupling component to give disazo dystufis. The coupling product with1-hydroxynaphthalene-4-sulphonic acid is an orange brown powder, dyeingwool orange -red shades, which become brownish-red by afterchroming. Thesame dyestuii will be obtained if the non-saponified monoazo dyestufi iscoupled with l-hydroxynaphthalene-4- sulphonic acid and subjected tosaponification.

If one uses instead of l-hydroxynaphthalene- 4-sulphonic acid, theequivalent quantity of 2,5- dichloro-4- sulpho l-phenyl-S-pyrazolone, adisazo dyestuff will be obtained, which is an orange-brown powder dyeingwool yellow shades, which become brown-orange by afterchroming.

The following table illustrates further examples of dyestuffs with theirrespective shades:

Monoazo dyestufis After saponification shade on wool Diazo componentCoupling component Dry powder Direct After-chromed UN(SO207H7)2l-naphthol-i-sulphonic acid Violet Orange-red. Violet.

N(S 0 0 11 4-sulpl1o-phenylmethyl-pyrazolone-. Yellow YellowBrownish-red.

D 2,5'-dichloro-4-sulphophenyl-methyl do do Brownish-orange.

pyrazolone. DolA-naphthol-sulphonic acid Orange-red" Violet. Do.1-naphthol-3,6-disulphonic acid Orange Do. Do1-(2-n1ethyl-3-amino-5-sulpho- Yellow Orange.

phenyl)-3-methyl-5-pyrazolone. Do 2-amino-8-naphthol-6-sulphonicacidDark-brown Bluish-red Dark-blue.

COGH: lA-naphthol-sulphonic acld Red Orange-red. Violet.

H; A l t l 7 N(SO;O H1)1 2-naphthol-6-sulphonlc 801d Dark O r a n g eDo. I brown.

Do. 2-naphthol-6,8-disiflphonic acid Red Orange Red-violet. Dn1-hydroxy-8-phenylamino-nephtha- Dark Violet Dark-green.

lene-E-sulphonic acid. Do. 1-naphth0l-4-sulphonic acid Red Orange-red.B1l1lSh- V10let. Do 4'-sulphophenyl-methyl-pyrazolona. Yellow YellowBrowmsh-red.

11TH: I

N(SO2 -CyH1)2 fi-mnh Brown-red.. Violet.

Do.. m-Phen-ylene-diamine Red-brown Orange Brown. DnPhenylmethyl-pyrazolon Yellow Yellow Orange. Do- Resorcinol OrangedoBrown-red.

brown. Do p-CtNnl Yellow Reddish- Corinth.

; 1 Yellow. Do- N-acetyl-p-amlnophenol do Brovlvlnish Violet-brown.

. ye ow. Do 1-acetylamlno-7-naphthol Brownish Brownish Blackblue.

- violet. red. D Acetoacetic anilide Yellow Yellow Yellow.

Alter saponification shade on wool Diazo component Coupling componentDry powder:

Direct After-chromed S 101 1 .N\ v SOQCHB NH l-naphthol-i-sulphonic acidRed Orange-mi- Violet.

D 2-naphthol+sulphonic acid Dark O r a n g e Brownish-violet.

brown. 's 010 H:

NH; 4-sulpho-phenyl-methyl-pyrazolone Yellow Yellow Orange.

N( S 020 11 l-naphthoi-Qsulphonlc acid Red Yollgwish Navy-blue.

OH N02 N (S 0101111): 1-naphtho1-4-sulphonic aci D Bluish-red.-Black-blue.

N(S 0101111); B-naphtho] d0.-......- Red Grey-blue.

Polyazo dyestufls After saponiflcation shade on Dry wooi Dlam componentCoupling component powder Direct After-chromed NH,-)tesotcinol(sulphanilic acid-.. Brow-11.. Orange-brown... Brown.

N(S 02071517): Dark... Yellow-brown. Violet-redbrown.

SO H

Do m-pheny]ene-dian1ine -4-nitro-2-amino-1-phenoldo Reddish-brown.Dark-brown.

N(SOzC1H1)2 -)2 mol. of l-naphthoM-sulphonic acid, Red Bluish-rodViolet.

OHF' NH;

After saponification shade on D t 1i t Dry wool iazo componen oup ngcomponen powder Direct After-chromed N(SOrG1H1)a I V Qmol.of1-phenylamino-S-naphthoI- l-sulphonic acid Dark..- Dark-blue Green.

0H3- NH] IIIH:

VN(SO2O7H7)1, r -)1-(2-methyl-3-amino-5-- 1-naphthol-4-sulphonic Orange-Orange-red. Brownish-red.

sulpho-phenyD-El-meacid. brown. thyl-5-pyrazolone. OH:-

N'Hg

N(SO2C7H7)2 'do -92,5-dichloro-4-sulpho-1- ..do. Yellow Brown-orange.

ghelnyla-mlethyl-fl-mev. I

- azo one. CH Y P3 7 Diazo component Coupling component N(S 030 111):resorcinol dianisidine Dark powder, on cot- 2 ton violet-brown,aftertreated with cop- SOaH- per-salts reddishbrown.

NH; I

N(S 010 B): resorclnol-benzidinersalicy1ic acid Dark powder, orangebrownon cotton,

browner with copper- SOaH salts.

Do 2-amino-B-hydroxy-naphthalene]- benzidinesa1icylic. Dark-brownpowder, 7-sulphonic acid. acid. reddish-brown on cotton, browner withcopper-salts.

Do resorcinol-amidoazo-toluene-monosnlphonic acid Dark powder,onleather: reddish-brown, the complex coppercompound on leather brown.

Do -)resorcino1l-amino-S-hydroxy-naphthalene-3,6-disulphonic Blackpowder, on

acid.- leather: brown, copper-complex: violetbrown.

What I claim is:

1. A process for the manufacture of copper complex compounds, comprisingthe treatment with copper yielding agents of polyazo dyestufis of thegeneral formula NH-S 0207111 AMP c (I with copper yielding agents ofpolyazo dyestufis of the general formula wherein X stands for a memberof the group consisting of hydrogen, alkyl and sulpho, and R stands forthe radical deriving from a diazotized compound selected from the classconsisting of diazotable aromatic compounds.

3. A process for the manufacture of a copper complex compound,comprising the treatment with copper yielding agents of the dyestuif ofthe general formula 4. A process for the manufacture of a copper complexcompound, comprising the treatment with copper yielding agents of thedyestufi of the general formula 5. The copper complex compounds ofpolyazo dyestuffs of the general formula wherein X stands for a memberof the group consisting of hydrogen, alkyl and sulpho, and R stands forthe radical deriving from a. diazotized compound selected from the classconsisting of diazotable aromatic compounds, which are watersolublecompounds suitable for dyeing animal and cellulose fibres.

7. The copper complex compound of the polyazo dyestufi of the formulaNIH-50101111 N=N N=NQON=N OOOH on OH 8. The copper complex compound ofthe polyazo dyestuff of the formula.

WAL'IER WEI-IRE.

